Deep phenotyping of PROM1-associated retinal degeneration

BACKGROUND/AIMS

The purpose of this study was to investigate retinal structure in detail of subjects with autosomal-dominant (AD) and autosomal-recessive (AR) PROM1-associated retinal degeneration (PROM1-RD), study design: institutional, cross-sectional study.

METHODS

Four eyes from four subjects (three with AD and one with AR) PROM1-RD were investigated by ophthalmic examination including best-corrected visual acuity (BCVA) and multimodal retinal imaging: fundus autofluorescence (FAF), spectral-domain optical coherence tomography (SD-OCT) and adaptive optics scanning light ophthalmoscopy. Quantitative assessment of atrophic lesions determined by FAF, thickness of individual retinal layers and cone photoreceptor quantification was performed.

RESULTS

BCVA ranged from 20/16 to 20/200. Initial pathological changes included the presence of hyperautofluorescent spots on FAF imaging, while later stages demonstrated discrete areas of atrophy. In all patients, thinning of the outer retinal layers on SD-OCT with varying degrees of atrophy could be detected depending on disease-causing variants and age. Cone density was quantified both in central and/or at different eccentricities from the fovea. Longitudinal assessments were possible in two patients.

CONCLUSIONS

PROM1-RD comprises a wide range of clinical phenotypes. Depending on the stage of disease, the cone mosaic in PROM1-RD is relatively preserved and can potentially be targeted by cone-directed interventions.

Progression of PROM1-Associated Retinal Degeneration as Determined by Spectral-Domain Optical Coherence Tomography Over a 24-Month Period

PURPOSE

To evaluate the progression of atrophy as determined by spectral-domain optical coherence tomography (SD-OCT) in patients with molecularly confirmed PROM1-associated retinal degeneration (RD) over a 24-month period.

DESIGN

International, multicenter, prospective case series.

METHODS

A total of 13 eyes (13 patients) affected with PROM1-associated RD were enrolled at 5 sites and SD-OCT images were obtained at baseline and after 24 months. Loss of mean thickness (MT) and intact area were estimated after semi-automated segmentation for the following individual retinal layers in the central subfield (CS), inner ring, and outer ring of the ETDRS grid: retinal pigment epithelium (RPE), outer segments (OS), inner segments (IS), outer nuclear layer (ONL), inner retina (IR), and total retina (TR).

RESULTS

Statistically significant losses of thickness of RPE and TR were detected in the CS and inner ring and of ONL and IS in the outer ring (all P < .05); a statistically significant decrease in the intact area of RPE and IS was observed in the inner ring, and of ONL in the outer ring (all P < .05); the change in MT and the intact area of the other layers showed a trend of decline over an observational period of 24 months.

CONCLUSIONS

Significant thickness losses could be detected in outer retinal layers by SD-OCT over a 24-month period in patients with PROM1-associated retinal degeneration. Loss of thickness and/or intact area of such layers may serve as potential endpoints for clinical trials that aim to slow down the disease progression of PROM1-associated retinal degeneration.

Identification of a cryptic functional apolipophorin-III domain within the Prominin-1 gene of Litopenaeus vannamei

The Apolipophorin-III (apoLp-III) is reported as an essential protein element in lipids transport and incorporation in lepidopterans. Structurally, apoLp-III has an α-helix bundle structure composed of five α-helices. Interestingly, classic studies proposed a structural switch triggered by its interaction with lipids, where the α-helix bundle opens. Currently, the study of the apoLp-III has been limited to insects, with no homologs identified in other arthropods. By implementing a structure-based search with the Phyre2 algorithm surveying the shrimp Litopenaeus vannamei's transcriptome, we identified a putative apoLp-III in this farmed penaeid (LvApoLp-III). Unlike canonical apoLp-III, the LvApoLp-III was identified as an internal domain within the transmembrane protein Prominin-1. Structural modeling using the template-based Phyre2 and template-free AlphaFold algorithms rendered two distinct structural topologies: the α-helix bundle and a coiled-coil structure. Notably, the secondary structure composition on both models was alike, with differences in the orientation and distribution of the α-helices and hydrophobic moieties. Both models provide insights into the classical structural switch induced by lipids in apoLp-III. To corroborate structure/function inferences, we cloned the synthetic LvApoLp-III domain, overexpressed, and purified the recombinant protein. Circular dichroism measurements with the recombinant LvApoLp-III agreed with the structural models. In vitro liposome interaction demonstrated that the apoLp-III domain within the PROM1 of L.vannamei associated similarly to exchangeable apolipoproteins. Altogether, this work reports the presence of an apolipophorin-III domain in crustaceans for the first time and opens questions regarding its function and importance in lipid metabolism or the immune system.

Clinical importance of serum and pleural fluid prominin-1 and hypoxia-inducible factor-1α concentration in the evaluation of lymph node involvement in patients with malignant pleural effusion

Introduction

Malignant pleural effusion (MPE) and lymph node metastasis (LNM) presence are poor prognostic factors that have importance for cancer patients. The study objective was to determine whether hypoxia-inducible factor-1α (HIF-1α) and prominin-1 (CD133) in pleural fluid (P) and serum (S) could be used as biomarkers for diagnosis of lymph node involvement in patients with MPE.

Materials and methods

Fifty-six patients with MPE and 30 healthy control subjects were included. Computerized tomography (CT) and positron emission tomography (PET) were used to diagnose pleural effusion. Patients with malignant cells in pleural fluid cytological examination were included in the MPE group. Thirty-five patients with lymph node metastases on CT were included in the LNM-positive MPE group. Serum and pleural fluid HIF-1α and CD-133 concentrations were measured manually via enzyme-linked immunosorbent assay (ELISA).

Results

Serum concentrations of HIF-1α and CD133 were higher in MPE patients. It was found that CD133/HIF-1α (S) ratio was higher in the malignant patient group with positive lymph node involvement than in the negative group, while concentrations of HIF-1α (P) were lower. Pleural fluid HIF-1α and CD133/HIF-1α (S) ratio had sufficient performance in diagnosing lymphatic metastases in patients with MPE (AUC = 0.90 and 0.83, respectively).

Conclusions

In conclusion, serum HIF-1α and CD133 concentrations were higher in patients with MPE, consistent with our hypothesis. Concentrations of HIF-1α (P) and CD133/HIF-1α (S) ratio can be used as biomarkers in diagnosing lymph node involvement in MPE patients, according to this experiment.

New iron export pathways acting via holo-ferritin secretion

Ferritin is a spherical nanocage protein for iron storage, composed of 24 light- or heavy-polypeptide chain subunits. A single ferritin molecule can carry up to 4500 iron atoms in its core, which plays an important role in suppressing intracellular iron toxicity. Serum ferritin levels are used as a marker for the total amount of iron stored in the body. Most serum ferritin is iron-free (apo-ferritin) and it is unclear how ferritin is released from cells. Ferritin is secreted into serum via extracellular vesicles (EVs) or the secretory autophagy pathway but not via the classical endoplasmic reticulum (ER)-to-Golgi secretion pathway. We recently discovered that the level of tetraspanin CD63, a common EV marker, is post-transcriptionally regulated by the intracellular iron level and both CD63 and ferritin expression is induced by iron loading. Ferritin is incorporated into CD63(+)-EVs through the ferritin-specific autophagy adapter molecule, NCOA4, and then secreted from cells. EV production differs drastically depending on cell type and physiological conditions. Extracellular matrix detached cells express pentaspanin prominin 2 and prominin 2(+)-EVs secrete ferritin independently of NCOA4 trafficking. Ferritin is tightly bound to iron in EVs and functions as an iron-carrier protein in the extracellular environment. Cells can suppress ferroptosis by secreting holo-ferritin, which reduces intracellular iron concentration. However, this exposes the neighboring cells receiving the secreted holo-ferritin to a large excess of iron. This results in cellular toxicity through increased generation of reactive oxygen species (ROS). Here we review the machinery by which ferritin is incorporated into EVs and its role as an intercellular communication molecule.

Prominin 2 decreases cisplatin sensitivity in non-small cell lung cancer and is modulated by CTCC binding factor

BACKGROUND

Non-small cell lung cancer (NSCLC) is the major pathological type of lung cancer and accounts for the majority of lung cancer-related deaths worldwide. We investigated the molecular mechanism of prominin 2 (PROM2) involved in cisplatin resistance in NSCLC.

PATIENTS AND METHODS

The GEO database was analyzed to obtain differential genes to target PROM2. Immunohistochemistry and western blotting were used to detect protein expression levels. To examine the role of PROM2 in NSCLC, we overexpressed or knocked down PROM2 by transfection of plasmid or small interfering RNA. In functional experiments, CCK8 was used to detect cell viability. Cell migration and invasion and apoptosis were detected by transwell assay and flow cytometry, respectively. Mechanistically, the regulation of PROM2 by CTCF was detected by ChIP-PCR. In vivo experiments confirmed the role of PROM2 in NSCLC.

RESULTS

GEO data analysis revealed that PROM2 was up-regulated in NSCLC, but its role in NSCLC remains unclear. Our clinical samples confirmed that the expression of PROM2 was markedly increased in NSCLC tissue. Functionally, Overexpression of PROM2 promotes cell proliferation, migration and invasion, and cisplatin resistance. CTCF up-regulates PROM2 expression by binding to its promoter region. In vivo experiments confirmed that PROM2 knockdown could inhibit tumor growth and increase the sensitivity of tumor cells to cisplatin.

CONCLUSIONS

PROM2 up-regulation in NSCLC can attenuate the sensitivity of NSCLC cells to cisplatin and promote the proliferation, migration and invasion of tumor cells. PROM2 may provide a new target for the treatment of NSCLC.

Proteasomes Are Critical for Maintenance of CD133+CD24+ Kidney Progenitor Cells

Kidney progenitor cells, although rare and dispersed, play a key role in the repair of renal tubules after acute kidney damage. However, understanding these cells has been challenging due to the limited access to primary renal tissues and the absence of immortalized cells to model kidney progenitors. Previously, our laboratory utilized the renal proximal tubular epithelial cell line, RPTEC/TERT1, and the flow cytometry technique to sort and establish a kidney progenitor cell model called Human Renal Tubular Precursor TERT (HRTPT) which expresses CD133 and CD24 and exhibits the characteristics of kidney progenitors, such as self-renewal capacity and multi-potential differentiation. In addition, a separate cell line was established, named Human Renal Epithelial Cell 24 TERT (HREC24T), which lacks CD133 expression and shows no progenitor features. To further characterize HRTPT CD133+CD24+ progenitor cells, we performed proteomic profiling which showed high proteasomal expression in HRTPT kidney progenitor cells. RT-qPCR, Western blot, and flow cytometry analysis showed that HRTPT cells possess higher proteasomal expression and activity compared to HREC24T non-progenitor cells. Importantly, inhibition of the proteasomes with bortezomib reduced the expression of progenitor markers and obliterated the potential for self-renewal and differentiation of HRTPT progenitor cells. In conclusion, proteasomes are critical in preserving progenitor markers expression and self-renewal capacity in HRTPT kidney progenitors.

Insights Into PROM1-Macular Disease Using Multimodal Imaging

Purpose

To describe the features of genetically confirmed PROM1-macular dystrophy in multimodal images.

Methods

Thirty-six (36) eyes of 18 patients (5-66 years; mean age, 42.4 years) were prospectively studied by clinical examination and multimodal imaging. Short-wavelength autofluorescence (SW-AF) and quantitative fundus autofluorescence (qAF) images were acquired with a scanning laser ophthalmoscope (HRA+OCT, Heidelberg Engineering) modified by insertion of an internal autofluorescent reference. Further clinical testing included near-infrared autofluorescence (NIR-AF; HRA2, Heidelberg Engineering) with semiquantitative analysis, spectral domain-optical coherence tomography (HRA+OCT) and full-field electroretinography. All patients were genetically confirmed by exome sequencing.

Results

All 18 patients presented with varying degrees of maculopathy. One family with individuals affected across two generations exhibited granular fleck-like deposits across the posterior pole. Areas of granular deposition in SW-AF and NIR-AF corresponded to intermittent loss of the ellipsoid zone, whereas discrete regions of hypoautofluorescence corresponded with a loss of outer retinal layers in spectral-domain optical coherence tomography scans. For 18 of the 20 eyes, qAF levels within the macula were within the 95% confidence intervals of healthy age-matched individuals; nor was the mean NIR-AF signal increased relative to healthy eyes.

Conclusions

Although PROM1-macular dystrophy (Stargardt disease 4) can exhibit phenotypic overlap with recessive Stargardt disease, significantly increased SW-AF levels were not detected. As such, elevated bisretinoid lipofuscin may not be a feature of the pathophysiology of PROM1 disease. The qAF approach could serve as a method of early differential diagnosis and may help to identify appropriate disease targets as therapeutics become available to treat inherited retinal disease.

Molecular Regulation of Autophagy and Asymmetric Cell Division by Cancer Stem Cell Marker CD133

CD133, also called prominin-1, is widely known as a cancer stem cell marker, and its high expression correlates with a poor prognosis in many cancers. CD133 was originally discovered as a plasma membranous protein in stem/progenitor cells. It is now known that Src family kinases phosphorylate the C-terminal of CD133. However, when Src kinase activity is low, CD133 is not phosphorylated by Src and is preferentially downregulated into cells through endocytosis. Endosomal CD133 then associates with HDAC6, thereby recruiting it to the centrosome via dynein motors. Thus, CD133 protein is now known to localize to the centrosome as endosomes as well as to the plasma membrane. More recently, a mechanism to explain the involvement of CD133 endosomes in asymmetric cell division was reported. Here, we would like to introduce the relationship between autophagy regulation and asymmetric cell division mediated by CD133 endosomes.

Eradication of Heterogeneous Tumors by T Cells Targeted with Combination Bispecific Chemically Self-assembled Nanorings

Cancer stem-like cells (CSCs) are often the root cause of refractive relapse due to their inherent resistance to most therapies and ability to rapidly self-propagate. Recently, the antigen CD133 has been identified as a CSC marker on several cancer types and αCD133 therapies have shown selective targeting against CSCs with minimal off-target toxicity. Theoretically, by selectively eliminating CSCs, the sensitivity to bulk tumor-targeting therapies should be enhanced. Previously, our laboratory has developed bispecific chemically self-assembled nanorings (CSANs) that successfully induced T-cell eradication of EpCAM-positive (EpCAM+) tumors. We reasoned that targeting both CSCs [CD133-positive (CD133+)] and the bulk tumor (EpCAM+) simultaneously using our CSAN platform should produce a synergistic effect. We evaluated αCD133/αCD3 CSANs as both a single agent and in combination with αEpCAM/αCD3 CSANs to treat triple-negative breast cancer (TNBC) cells, which express a subpopulation of CD133+ cancer stem cells and EpCAM+ bulk tumor cells. Furthermore, an orthotopic breast cancer model validated the ability of αCD133 and αEpCAM targeting to combine synergistically in the elimination of TNBC MDA-MB-231 cells. Complete tumor eradication only occurred when EpCAM and CD133 were targeted simultaneously and lead to full remission in 80% of the test mice. Importantly, the depletion and enrichment of CD133 TNBCs highlighted the role of CD133+ cancer cells in regulating tumor growth and progression. Collectively, our results demonstrate that dual targeting with bispecific CSANs can be effective against heterogenous tumor cell populations and that elimination of primary and CD133+ CSCs may be necessary for eradication of at least a subset of TNBC.

Oxidized low-density lipoprotein stimulates CD206 positive macrophages upregulating CD44 and CD133 expression in colorectal cancer with high-fat diet

BACKGROUND

Oxidized low-density lipoprotein (ox-LDL), which is abnormally increased in the serum of colorectal cancer (CRC) patients consuming a high-fat diet (HFD), may be one of the risk factors for the development of CRC. Ox-LDL exerts a regulatory effect on macrophages and may influence CRC through the tumor microenvironment. The role of ox-LDL in CRC remains unclear.

AIM

To investigate the role of ox-LDL through macrophages in HFD associated CRC.

METHODS

The expression of ox-LDL and CD206 was detected in colorectal tissues of CRC patients with hyperlipidemia and HFD-fed mice by immunofluorescence. We stimulated the macrophages with 20 μg/mL ox-LDL and assessed the expression levels of CD206 and the cytokines by cell fluorescence and quantitative polymerase chain reaction. We further knocked down LOX-1, the surface receptor of ox-LDL, to confirm the function of ox-LDL in macrophages. Then, LoVo cells were co-cultured with the stimulated macrophages to analyze the CD44 and CD133 expression by western blot.

RESULTS

The expression of ox-LDL and the CD206 was significantly increased in the stroma of colorectal tissues of CRC patients with hyperlipidemia, and also upregulated in the HFD-fed mice. Moreover, an increased level of CD206 and decreased level of inducible nitric oxide synthase were observed in macrophages after ox-LDL continuous stimulation. Such effects were inhibited when the surface receptor LOX-1 was knocked down in macrophages. Ox-LDL could induce CD206+ macrophages, which resulted in high expression of CD44 and CD133 in co-cultured LoVo cells.

CONCLUSION

Ox-LDL stimulates CD206+ macrophages to upregulate CD44 and CD133 expression in HFD related CRC.

Single-cell sequencing reveals CD133+CD44−-originating evolution and novel stemness related variants in human colorectal cancer

Background

Tumor heterogeneity of human colorectal cancer (CRC)-initiating cells (CRCICs) in cancer tissues often represents aggressive features of cancer progression. For high-resolution examination of CRCICs, we performed single-cell whole-exome sequencing (scWES) and bulk cell targeted exome sequencing (TES) of CRCICs to investigate stemness-specific somatic alterations or clonal evolution.

Methods

Single cells of three subpopulations of CRCICs (CD133⁺CD44⁺, CD133⁻CD44⁺, and CD133⁺CD44⁻ cells), CRC cells (CRCCs), and control cells from one CRC tissue were sorted for scWES. Then, we set up a mutation panel from scWES data and TES was used to validate mutation distribution and clonal evolution in additional 96 samples (20 patients) those were also sorted into the same three groups of CRCICs and CRCCs. The knock-down experiments were used to analyze stemness-related mutant genes. Neoantigens of these mutant genes and their MHC binding affinity were also analyzed.

Findings

Clonal evolution analysis of scWES and TES showed that the CD133⁺CD44⁻ CRCICs were the likely origin of CRC before evolving into other groups of CRCICs/CRCCs. We revealed that AHNAK2, PLIN4, HLA-B, ALK, CCDC92 and ALMS1 genes were specifically mutated in CRCICs followed by the validation of their functions. Furthermore, four predicted neoantigens of AHNAK2 were identified and validated, which might have applications in immunotherapy for CRC patients.

Interpretation

All the integrative analyses above revealed clonal evolution of CRC and new markers for CRCICs and demonstrate the important roles of CRCICs in tumorigenesis and progression of CRCs.

Funding

A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.

PROM1, CXCL8, RUNX1, NAV1 and TP73 genes as independent markers predictive of prognosis or response to treatment in two cohorts of high-grade serous ovarian cancer patients

Considering the vast biological diversity and high mortality rate in high-grade ovarian cancers, identification of novel biomarkers, enabling precise diagnosis and effective, less aggravating treatment, is of paramount importance. Based on scientific literature data, we selected 80 cancer-related genes and evaluated their mRNA expression in 70 high-grade serous ovarian cancer (HGSOC) samples by Real-Time qPCR. The results were validated in an independent Northern American cohort of 85 HGSOC patients with publicly available NGS RNA-seq data. Detailed statistical analyses of our cohort with multivariate Cox and logistic regression models considering clinico-pathological data and different TP53 mutation statuses, revealed an altered expression of 49 genes to affect the prognosis and/or treatment response. Next, these genes were investigated in the validation cohort, to confirm the clinical significance of their expression alterations, and to identify genetic variants with an expected high or moderate impact on their products. The expression changes of five genes, PROM1, CXCL8, RUNX1, NAV1, TP73, were found to predict prognosis or response to treatment in both cohorts, depending on the TP53 mutation status. In addition, we revealed novel and confirmed known SNPs in these genes, and showed that SNPs in the PROM1 gene correlated with its elevated expression.

METTL3 promotes oxaliplatin resistance of gastric cancer CD133+ stem cells by promoting PARP1 mRNA stability

Oxaliplatin is the first-line regime for advanced gastric cancer treatment, while its resistance is a major problem that leads to the failure of clinical treatments. Tumor cell heterogeneity has been considered as one of the main causes for drug resistance in cancer. In this study, the mechanism of oxaliplatin resistance was investigated through in vitro human gastric cancer organoids and gastric cancer oxaliplatin-resistant cell lines and in vivo subcutaneous tumorigenicity experiments. The in vitro and in vivo results indicated that CD133+ stem cell-like cells are the main subpopulation and PARP1 is the central gene mediating oxaliplatin resistance in gastric cancer. It was found that PARP1 can effectively repair DNA damage caused by oxaliplatin by means of mediating the opening of base excision repair pathway, leading to the occurrence of drug resistance. The CD133+ stem cells also exhibited upregulated expression of N6-methyladenosine (m6A) mRNA and its writer METTL3 as showed by immunoprecipitation followed by sequencing and transcriptome analysis. METTTL3 enhances the stability of PARP1 by recruiting YTHDF1 to target the 3'-untranslated Region (3'-UTR) of PARP1 mRNA. The CD133+ tumor stem cells can regulate the stability and expression of m6A to PARP1 through METTL3, and thus exerting the PARP1-mediated DNA damage repair ability. Therefore, our study demonstrated that m6A Methyltransferase METTL3 facilitates oxaliplatin resistance in CD133+ gastric cancer stem cells by Promoting PARP1 mRNA stability which increases base excision repair pathway activity.

Expressions of Putative Cancer Stem Cell Markers, CD44 and CD133, are Correlated with Pathological Tumour Stage in Gastric Adenocarcinoma

OBJECTIVE

To analyse partial and total gastrectomy specimen in items of immunohistochemical staining of the stem cell CD44 and CD133; and to determine their relationship to pathological stage, other clinicopathological prognostic parameters, and their predictive value.

STUDY DESIGN

Derscriptive study.

PLACE AND DURATION OF STUDY

Department of Pathology, Bolu Abant Izzet Baysal University, Medical School, Turkey, from 2013 to 2018.

METHODOLOGY

Eighty-three cases, diagnosed with adenocarcinoma from stomach partial and total gastrectomy slides and blocks, were included in the study. Adenocarcinoma cases, that had received neoadjuvant treatment before gastrectomy, cases diagnosed with lymphoma and other malignancies and cases of resection performed for reasons other than tumours, were excluded. Formalin-fixed and paraffin wax-embedded gastric adenocarcinoma blocks were sliced. CD44 and CD133 were stained onto the slides in a Leica Bond Max staining device in compliance with immunohistochemical staining datasheets. Membranous staining for CD44 and cytoplasmic, membranous or luminal staining for CD133 were evaluated. Mann-Whitney U-test and Kruskal- Wallis test were used for group comparisons. For pairwise comparisons, post-hoc Dunn's tests were used. The results were assessed on the significance level of p <0.05. The analyses were performed using the Statistical Package for the Social Sciences version 22.0 for Windows (SPSS Inc., Chicago, Illinois, USA).

RESULTS

Considering CD44 and CD133 expressions in terms of pathological stage, there was significantly more intense expression in the T3 and T4 cases (p=0.009, and p=0.002, respectively).

CONCLUSION

Although CD44 is regarded to be associated with more prognostic parameters compared to CD133, both immunohistochemical stains were shown to be related to pathological stage. Thus, these may be guiding for determining the tumour depth. Key Words: Gastric adenocarcinoma, CD44, CD133, Stem cell marker, Prognosis.

Combined Poziotinib with Manidipine Treatment Suppresses Ovarian Cancer Stem-Cell Proliferation and Stemness

Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy in women worldwide, with an overall 5 year survival rate below 30%. The low survival rate is associated with the persistence of cancer stem cells (CSCs) after chemotherapy. Therefore, CSC-targeting strategies are required for successful EOC treatment. Pan-human epidermal growth factor receptor 4 (HER4) and L-type calcium channels are highly expressed in ovarian CSCs, and treatment with the pan-HER inhibitor poziotinib or calcium channel blockers (CCBs) selectively inhibits the growth of ovarian CSCs via distinct molecular mechanisms. In this study, we tested the hypothesis that combination treatment with poziotinib and CCBs can synergistically inhibit the growth of ovarian CSCs. Combined treatment with poziotinib and manidipine (an L-type CCB) synergistically suppressed ovarian CSC sphere formation and viability compared with either drug alone. Moreover, combination treatment synergistically reduced the expression of stemness markers, including CD133, KLF4, and NANOG, and stemness-related signaling molecules, such as phospho-STAT5, phospho-AKT, phospho-ERK, and Wnt/β-catenin. Moreover, poziotinib with manidipine dramatically induced apoptosis in ovarian CSCs. Our results suggest that the combinatorial use of poziotinib with a CCB can effectively inhibit ovarian CSC survival and function.

Prominin-2 Suppresses Ferroptosis Sensitivity

Ferroptosis causes clinically relevant amounts of necrosis during the course of heart attacks and acute kidney injury. However, ferroptosis is still a very young research field. In this issue of Developmental Cell, Brown et al. describe the pentaspan membrane glycoprotein prominin-2 as a novel endogenous ferroptosis inhibitor.

Calcitonin induces stem cell-like phenotype in prostate cancer cells

Stem cell-like-cancer cells are key drivers of tumor growth, metastasis, and relapse of cancer following remission. Prostate stem cell-like cancer cells isolated from human prostate cancer (PC) biopsies express CD44+/α2β1 hi/CD133+ cell surface markers and can self-renew in vitro. Expression of calcitonin (CT) and its receptor (CTR) is frequently elevated in PCs and activation of CT-CTR axis in non-invasive PC cells induces an invasive phenotype. We investigated whether CT-CTR autocrine axis induces stem cell-like phenotype in two PC cell lines. CT-CTR axis in these cell lines was activated by enforced expression of CTR. The cells were then examined for the changes in the expression of CD44 and CD133, collagen adherence, tumorigenic, metastatic and repopulating characteristics. The activation of CT-CTR axis led to a large increase in adherence to collagen and a remarkable increase of CD44 and CD133 in PC-3 and LNCaP cells. This was accompanied by a strong increase in tumorigenic, metastatic and repopulation properties of PC cells. However, the mutation of CTR-C PDZ-binding site in CTR almost abolished CTR-mediated increases in stem cell-like characteristics of PC cells. These results support an important role for CT-CTR axis in the progression of PC from localized cancer to an aggressive form, and a majority of proinvasive CTR actions may be mediated through its interaction with its partner protein at the PDZ-binding site. These results suggest that CT/CTR can serve as a valuable target to prevent the generation of stem-like PC cells.

Novel Cancer Stem Marker and Its Applicability for Grading Primary Human Gliomas

Poorly differentiated cell populations including tumor-initiating stem cells have been demonstrated to display a unique ability to natively internalize fragmented double-stranded DNA. Using this feature as a marker, we show that 0.1% to 6% of human glioblastoma cells from the bioptates can effectively internalize a fluorescently labeled DNA probe. Of these, using samples from 3 patients, 66% to 100% cells are also positive for CD133, a well-established surface marker of tumor-initiating glioma stem cells. Using the samples from primary malignant brain lesions (33 patients), we demonstrate that tumor grading significantly correlates ( R = .71) with the percentage of DNA-internalizing cells. No such correlation is observed for relapse samples (18 patients).

[The expression and significance of CD(276) and CD(133) in colorectal cancer and precancerous lesions]

In order to study the significance of CD(276) and CD(133) in the development and progression of colorectal cancer (CRC), the expression of CD(276) and CD(133) was detected by immunohistochemistry in CRC and precancerous lesions. The results showed that the intensity of CD(276) and CD(133) in CRC samples was higher than that in adenoma group and non-adenoma group. CD(276) and CD(133) single and double positive expression were significantly correlated with CRC lymph node metastasis, distant metastasis and survival. CD(276) and CD(133) are significantly correlated to the development and progression of CRC and associated with poor prognosis.

Mefloquine targets β-catenin pathway and thus can play a role in the treatment of liver cancer

The current study was designed and performed to investigate the effect of mefloquine on the proliferation and tumor formation potential of liver cancer stem cells. CD133 + HepG2 cells were identified using MACS and showed markedly higher tumor formation potential compared to the parental cells. The secondary tumors formed by CD133 + cells were markedly large in size and more in number compared to the parental cells. Mefloquine treatment of CD133 + HepG2 cells inhibited the proliferation selectively in concentration based manner. The rate of proliferation was inhibited to 82 and 12% in parental and CD133 + sphere forming cells, respectively on treatment with 10 μM concentration of mefloquine. The number of secondary tumors formed by primary tumors was decreased significantly on treatment with 10 μM mefloquine concentration. Treatment of the liver cancer stem cells with mefloquine markedly decreased the potential to undergo self-renewal at 10 μM concentration after 48 h. The results from western blot analysis showed significantly higher expression of cancer stem cell molecules β-catenin and cyclin D1 in LCSCs. Treatment of the LCSCs with various concentrations of mefloquine reduced the expression levels of β-catenin and cyclin D1. Administration of the CD133 + cell tumor xenografts in the mice led to the formation of large sized tumors in the control group. However, the tumor growth was inhibited significantly in the mice on treatment with 10 mg/kg doses of mefloquine after day 21. The tumor weight was significantly lower in the animals of mefloquine treatment group compared to the control group. Thus, mefloquine treatment inhibits self-renewal and proliferation potential of cells through targeting β-catenin pathway.

MPEG-CS/Bmi-1RNAi Nanoparticles Synthesis and Its Targeted Inhibition Effect on CD133+ Laryngeal Stem Cells

Previous studies have confirmed that CD133+ cells in laryngeal tumor tissue have the characteristics of cancer stem cells. Bmi-1 gene expression is central to the tumorigenicity of CD133+ cells. In this study, we tried to develop a new siRNA carrier system using chitosan-methoxypolyethylene nanoparticles (CS-mPEG-NPs) that exhibit higher tumor-targeting ability and enhanced gene silencing efficacy in CD133+ tumor stem cells. It is hoped to block the self-renewal and kill the stem cells of laryngeal carcinoma. The mPEG-CS-Bmi-1RNAi-NPs were synthesized and their characters were checked. The changes in invasion ability and sensitivity to radiotherapy and chemotherapy of CD133+Hep-2 tumor cells were observed after Bmi-1 gene silencing. The mPEG-CS-Bmi-1RNAi-NPs synthesized in this experiment have a regular spherical form, a mean size of 139.70 ±6.40 nm, an encapsulation efficiency of 85.21 ± 1.94%, with drug loading capacity of 18.47 ± 1.83%, as well as low cytotoxicity, providing good protection to the loaded gene, strong resistance to nuclease degradation and high gene transfection efficiency. After Bmi-1 gene silencing, the invasion ability of CD133+ cells was weakened. Co-cultured with paclitaxel, the survival rates of CD133+Bmi-1RNAi cells were lower. After radiotherapy, the mean growth inhibition rate of CD133+/Bmi-1RNAi cells was significantly lower than CD133+ cells. In conclusion, the mPEG-CS nano-carrier is an ideal vector in gene therapy, while silencing the Bmi-1 gene can enhance the sensitivity of CD133+ tumor stem cells to chemoradiotherapy and abate their invasion ability.

Granulocyte colony-stimulating factor and autologous CD133-positive stem-cell therapy in liver cirrhosis (REALISTIC): an open-label, randomised, controlled phase 2 trial

BACKGROUND

Results of small-scale studies have suggested that stem-cell therapy is safe and effective in patients with liver cirrhosis, but no adequately powered randomised controlled trials have been done. We assessed the safety and efficacy of granulocyte colony-stimulating factor (G-CSF) and haemopoietic stem-cell infusions in patients with liver cirrhosis.

METHODS

This multicentre, open-label, randomised, controlled phase 2 trial was done in three UK hospitals and recruited patients with compensated liver cirrhosis and MELD scores of 11·0-15·5. Patients were randomly assigned (1:1:1) to receive standard care (control), treatment with subcutaneous G-CSF (lenograstim) 15 μg/kg for 5 days, or treatment with G-CSF for 5 days followed by leukapheresis and intravenous infusion of three doses of CD133-positive haemopoietic stem cells (0·2 × 106 cells per kg per infusion). Randomisation was done by Cancer Research UK Clinical Trials Unit staff with a minimisation algorithm that stratified by trial site and cause of liver disease. The coprimary outcomes were improvement in severity of liver disease (change in MELD) at 3 months and the trend of change in MELD score over time. Analyses were done in the modified intention-to-treat population, which included all patients who received at least one day of treatment. Safety was assessed on the basis of the treatment received. This trial was registered at Current Controlled Trials on Nov 18, 2009; ISRCTN, number 91288089; and the European Clinical Trials Database, number 2009-010335-41.

FINDINGS

Between May 18, 2010, and Feb 26, 2015, 27 patients were randomly assigned to the standard care, 26 to the G-CSF group, and 28 to the G-CSF plus stem-cell infusion group. Median change in MELD from day 0 to 90 was -0·5 (IQR -1·5 to 1·1) in the standard care group, -0·5 (-1·7 to 0·5) in the G-CSF group, and -0·5 (-1·3 to 1·0) in the G-CSF plus stem-cell infusion group. We found no evidence of differences between the treatment groups and control group in the trends of MELD change over time (p=0·55 for the G-CSF group vs standard care and p=0·75 for the G-CSF plus stem-cell infusion group vs standard care). Serious adverse events were more frequent the in G-CSF and stem-cell infusion group (12 [43%] patients) than in the G-CSF (three [11%] patients) and standard care (three [12%] patients) groups. The most common serious adverse events were ascites (two patients in the G-CSF group and two patients in the G-CSF plus stem-cell infusion group, one of whom was admitted to hospital with ascites twice), sepsis (four patients in the G-CSF plus stem-cell infusion group), and encephalopathy (three patients in the G-CSF plus stem-cell infusion group, one of whom was admitted to hospital with encephalopathy twice). Three patients died, including one in the standard care group (variceal bleed) and two in the G-CSF and stem-cell infusion group (one myocardial infarction and one progressive liver disease).

INTERPRETATION

G-CSF with or without haemopoietic stem-cell infusion did not improve liver dysfunction or fibrosis and might be associated with increased frequency of adverse events compared with standard care.

FUNDING

National Institute of Health Research, The Sir Jules Thorn Charitable Trust.

Enhancement of neovascularization with cord blood CD133+ cell-derived endothelial progenitor cell transplantation

The endothelial progenitor cells (EPCs) are responsible for postnatal vasculogenesis in physiological and pathological neovascularization and have been used for attenuating ischemic diseases. However, EPCs from umbilical cord blood (CB) were not well understood and the homing mechanisms of EPCs remain unclear. To determine the potential application of CB-derived EPCs, we established a culture system to induce the differentiation of CB cells into EPCs. Purified CB CD133+ cells proliferated and, after further vascular endothelial growth factor receptor 2 (VEGFR-2) antibody purification, differentiated into EPCs expressing endothelial markers, such as VE-cadherin, VEGFR-2, CD31, von Willebrand factor (vWF) and WeibelPalade bodies. These cells could also take up acetylated lower density lipoprotein (Ac-LDL) and bind Ulex europaeus agglutinin-1 (UEA-1).When expanded EPCs were transplanted via tail vein into nude mice, they incorporated into capillary networks in ischemic hindlimb, augmented neovascularization, and improved ischemic limb salvage. In addition, in ischemic tissue, there were elevated expressions of VEGF and stromal derived factor 1α???????????(SDF-1α), both of which had chemotactic effect on EPCs. Moreover, P-/E-selectins was found on mouse ischemic endothelium and P-selectin glycoprotein ligand-1 (PSGL-1) on CB-derived EPCs. Neutralizing antibody against PSGL-1 blocked the homing of EPCs to ischemic area by 61%. These results demonstrate that CB CD133+ cell-derived EPCs can be applied for therapeutic neovascularization in ischemic diseases, and reveal important roles of chemoattractants and adhesive molecules in the homing of EPCs.

Expression of Neuronal Markers in Differentiated Marrow Stromal Cells and CD133+ Stem-Like Cells

Bone marrow stromal cells, which normally give rise to bone, cartilage, adipose tissue, and hematopoiesis-supporting cells, have been shown to differentiate in vitro and in vivo into neural-like cells. In this study, we examined the expression of neuronal and glial markers in human marrow stromal cells under culture conditions appropriate for neural stem cells, and compared the unsorted cell population to bone marrow CD133+ stem-like cells using immunofluorescence, Western blot, and functional patch-clamp analysis. Overall, the expression of the early neuronal marker β3-tubulin was most pronounced in the presence of DMEM/F12 and neurotrophin 3 (NT3) or brain-derived neurotrophic factor (BDNF), when marrow stromal cells were cultured onto fibronectin. Electrophysiological examination, however, could not show fast sodium currents or functional neurotransmitter receptors in differentiated marrow stromal cells. CD133+ mesenchymal stem-like cells, but not CD34+/CD133– cells, generally showed a higher expression of neuronal markers than did unsorted marrow stromal cells, and differentiated CD133+ cells more resembled neuron-like cells.

Increased circulating stem cells and better cognitive performance in traumatic brain injury subjects following hyperbaric oxygen therapy

Traumatic brain injury (TBI) may cause persistent cognitive dysfunction. A pilot clinical study was performed to determine if hyperbaric oxygen (HBO₂) treatment improves cognitive performance. It was hypothesized that stem cells, mobilized by HBO₂ treatment, are recruited to repair damaged neuronal tissue. This hypothesis was tested by measuring the relative abundance of stem cells in peripheral blood and cognitive performance during this clinical trial. The subject population consisted of 28 subjects with persistent cognitive impairment caused by mild to moderate TBI suffered during military deployment to Iraq or Afghanistan. Fluorescence-activated cell sorting (FACS) analysis was performed for stem cell markers in peripheral blood and correlated with variables resulting from standard tests of cognitive performance and post-traumatic stress disorder: ImPACT, BrainCheckers and PCL-M test results. HBO₂ treatment correlated with stem cell mobilization as well as increased cognitive performance. Together these results support the hypothesis that stem cell mobilization may be required for cognitive improvement in this population.

Evaluation of the expressions pattern of miR-10b, 21, 200c, 373 and 520c to find the correlation between epithelial-to-mesenchymal transition and melanoma stem cell potential in isolated cancer stem cells

Small non-coding RNAs named microRNAs (miRNAs) modulate some functions and signaling pathways in skin epithelial cells and melanocytes. They also function as oncogenes or tumor suppressors in malignancies and tumor metastasis. We investigated the expression patterns of miRNAs, including miR-10b, 21, 200c, 373 and 520c, which regulate epithelial-to-mesenchymal transition (EMT) and metastasis in isolated cancer stem cells (CSCs) and non- CSCs. Six melanoma cell lines were tested for the expressions of stem cell markers. Melanoma stem cells were enriched via fluorescence-activated cell sorting (FACS) using the CD133 cell surface marker or spheroid culture. They were then characterized based on colony and sphere formation, and the expressions of stemness and EMT regulator genes and their invasion potential were assessed using real-time qRT-PCR and invasion assay. Our results indicate that cells enriched via sphere formation expressed all the stemness-related genes and had an enhanced number of colonies, spheres and invaded cells compared to cells enriched using the CD133 cell surface marker. Moreover, miRNAs controlling metastasis increased in the melanospheres. This may be related to the involvement of CSCs in the metastatic process. However, this must be further confirmed through the application of knockdown experiments. The results show that sphere formation is a useful method for enriching melanoma stem cells. Melanospheres were found to upregulate miR-10b, 21, 200c, 373 and 520c, so we suggest that they may control both metastasis and stemness potential.

[c-Myc regulation of ATP-binding cassette transporter reverses chemoresistance in CD133(+) colon cancer stem cells]

The present study was aimed to explore the role of c-Myc gene regulation in maintaining the self-renewal and drug-resistant properties of colon cancer stem cells (CSCs) and the underlying mechanism. CD133(+) cells were isolated by flow cytometry cell sorting from human HT29 cancer cells. A small interfering RNA (siRNA) against c-Myc was used, and the mRNA and protein expressions of c-Myc were investigated by real-time PCR and Western blotting, respectively. To evaluate the effect of c-Myc on the drug resistance of colon CSCs, CD133(+) cells transfected with c-Myc-siRNA were exposed to 5-FU, oxaliplatin, or their combination. The expressions of ATP-binding cassette (ABC) transporters, including ABCG2, ABCB5 and MDR-1, were detected by Western blotting. The results showed that c-Myc was highly expressed in CD133(+) colon CSCs, and the protein and mRNA expressions of c-Myc were effectively blocked by c-Myc siRNA. Furthermore, CD133(+) cells showed significantly increased survival rate in chemotherapy treatment, compared with CD133(-) cells. c-Myc silencing sensitized CD133(+) cells to chemotherapy-induced cytotoxicity and down-regulated the protein expression levels of ABCG2, MDR-1 and ABCB5. These results suggest c-Myc silencing may regulate the expressions of ABC transporters in colon CSCs, and enhance the sensitivity of CSCs to the chemotherapy.

Oct4 plays a crucial role in the maintenance of gefitinib-resistant lung cancer stem cells

Several recent studies have suggested that cancer stem cells (CSCs) are involved in resistance to gefitinib in non-small cell lung cancer (NSCLC). Oct4, a member of the POU-domain transcription factor family, has been shown to be involved in CSC properties of various cancers. We previously reported that Oct4 and the putative lung CSC marker CD133 were highly expressed in gefitinib-resistant persisters (GRPs) in NSCLC cells, and GRPs exhibited characteristic features of the CSCs phenotype. The aim of this study was to elucidate the role of Oct4 in the resistance to gefitinib in NSCLC cells with an activating epidermal growth factor receptor (EGFR) mutation. NSCLC cell lines, PC9, which express the EGFR exon 19 deletion mutation, were transplanted into NOG mice, and were treated with gefitinib in vivo. After 14-17 days of gefitinib treatment, the tumors still remained; these tumors were referred to as gefitinib-resistant tumors (GRTs). PC9-GRTs showed higher expression of Oct4 and CD133. To investigate the role of Oct4 in the maintenance of gefitinib-resistant lung CSCs, we introduced the Oct4 gene into PC9 and HCC827 cells carrying an activating EGFR mutation by lentiviral infection. Transfection of Oct4 significantly increased CD133-positive GRPs and the number of sphere formation, reflecting the self-renewal activity, of PC9 and HCC827 cells under the high concentration of gefitinib in vitro. Furthermore, Oct4-overexpressing PC9 cells (PC9-Oct4) significantly formed tumors at 1 × 10 cells/injection in NOG mice as compared to control cells. In addition, PC9-Oct4 tumors were more resistant to gefitinib treatment as compared to control cells in vivo. Finally, immunohistochemical analysis revealed that Oct4 was highly expressed in tumor specimens of EGFR-mutant NSCLC patients with acquired resistance to gefitinib. Collectively, these findings suggest that Oct4 plays a pivotal role in the maintenance of lung CSCs resistant to gefitinib in EGFR mutation-positive NSCLC.

Podoplanin discriminates distinct stromal cell populations and a novel progenitor subset in the liver

Podoplanin/gp38(+) stromal cells present in lymphoid organs play a central role in the formation and reorganization of the extracellular matrix and in the functional regulation of immune responses. Gp38(+) cells are present during embryogenesis and in human livers of primary biliary cirrhosis. Since little is known about their function, we studied gp38(+) cells during chronic liver inflammation in models of biliary and parenchymal liver fibrosis and steatohepatitis. Gp38(+) cells were analyzed using flow cytometry and confocal microscopy, and the expression of their steady state and inflammation-associated genes was evaluated from healthy and inflamed livers. Gp38(+) cells significantly expanded in all three models of liver injury and returned to baseline levels during regression of inflammation. Based on CD133 and gp38 expression in the CD45(-)CD31(-)Asgpr1(-) liver cell fraction, numerous subsets could be identified that were negative for CD133 (gp38(hi)CD133(-), gp38(low)CD133(-), and gp38(-)CD133(-)). Moreover, among the CD133(+) cells, previously identified as progenitor population in injured liver, two subpopulations could be distinguished based on their gp38 expression (gp38(-)CD133(+) and CD133(+)gp38(+)). Importantly, the distribution of the identified subsets in inflammation illustrated injury-specific changes. Moreover, the gp38(+)CD133(+) cells exhibited liver progenitor cell characteristics similar to the gp38(-)CD133(+) population, thus representing a novel subset within the classical progenitor cell niche. Additionally, these cells expressed distinct sets of inflammatory genes during liver injury. Our study illuminates a novel classification of the stromal/progenitor cell compartment in the liver and pinpoints a hitherto unrecognized injury-related alteration in progenitor subset composition in chronic liver inflammation and fibrosis.

Tobacco Smoke-Induced Brain White Matter Myelin Dysfunction: Potential Co-Factor Role of Smoking in Neurodegeneration

BACKGROUND

Meta-analysis studies showed that smokers have increased risk for developing Alzheimer's disease (AD) compared with non-smokers, and neuroimaging studies revealed that smoking damages white matter structural integrity.

OBJECTIVE

The present study characterizes the effects of side-stream (second hand) cigarette smoke (CS) exposures on the expression of genes that regulate oligodendrocyte myelin-synthesis, maturation, and maintenance and neuroglial functions.

METHODS

Adult male A/J mice were exposed to air (8 weeks; A8), CS (4 or 8 weeks; CS4, CS8), or CS8 followed by 2 weeks recovery (CS8 + R). The frontal lobes were used for histology and qRT-PCR analysis.

RESULTS

Luxol fast blue, Hematoxylin and Eosin stained histological sections revealed CS-associated reductions in myelin staining intensity and narrowing of the corpus callosum. CS exposures broadly decreased mRNA levels of immature and mature oligodendrocyte myelin-associated, neuroglial, and oligodendrocyte-related transcription factors. These effects were more prominent in the CS8 compared with CS4 group, suggesting that molecular abnormalities linked to white matter atrophy and myelin loss worsen with duration of CS exposure. Recovery normalized or upregulated less than 25% of the suppressed genes; in most cases, inhibition of gene expression was either sustained or exacerbated.

CONCLUSION

CS exposures broadly inhibit expression of genes needed for myelin synthesis and maintenance. These adverse effects often were not reversed by short-term CS withdrawal. The results support the hypothesis that smoking contributes to white matter degeneration, and therefore could be a key risk factor for a number of neurodegenerative diseases, including AD.

Identifying an ovarian cancer cell hierarchy regulated by bone morphogenetic protein 2

Whether human cancer follows a hierarchical or stochastic model of differentiation is controversial. Furthermore, the factors that regulate cancer stem-like cell (CSC) differentiation potential are largely unknown. We used a novel microfluidic single-cell culture method to directly observe the differentiation capacity of four heterogeneous ovarian cancer cell populations defined by the expression of the CSC markers aldehyde dehydrogenase (ALDH) and CD133. We evaluated 3,692 progeny from 2,833 cells. We found that only ALDH(+)CD133(+) cells could generate all four ALDH(+/-)CD133(+/-) cell populations and identified a clear branched differentiation hierarchy. We also observed a single putative stochastic event. Within the hierarchy of cells, bone morphologenetic protein 2 (BMP2) is preferentially expressed in ALDH(-)CD133(-) cells. BMP2 promotes ALDH(+)CD133(+) cell expansion while suppressing the proliferation of ALDH(-)CD133(-) cells. As such, BMP2 suppressed bulk cancer cell growth in vitro but increased tumor initiation rates, tumor growth, and chemotherapy resistance in vivo whereas BMP2 knockdown reduced CSC numbers, in vivo growth, and chemoresistance. These data suggest a hierarchical differentiation pattern in which BMP2 acts as a feedback mechanism promoting ovarian CSC expansion and suppressing progenitor proliferation. These results explain why BMP2 suppresses growth in vitro and promotes growth in vivo. Together, our results support BMP2 as a therapeutic target in ovarian cancer.

Intraportal Infusion of Bone Marrow Mononuclear or CD133+ Cells in Patients With Decompensated Cirrhosis: A Double-Blind Randomized Controlled Trial

The present study assessed the effects of intraportal infusions of autologous bone marrow-derived mononuclear cells (MNCs) and/or CD133+ cells on liver function in patients with decompensated cirrhosis. We randomly assigned 27 eligible patients to a placebo, MNCs, and/or CD133+ cells. Cell infusions were performed at baseline and month 3. We considered the absolute changes in the Model for End-Stage Liver Disease (MELD) scores at months 3 and 6 after infusion as the primary outcome. The participants and those who assessed the outcomes were unaware of the treatment intervention assignments. After 6 months, 9 patients were excluded because of liver transplantation (n=3), hepatocellular carcinoma (n=1), loss to follow-up (n=3), and death (n=2). The final analysis included 4 patients from the CD133+ group, 8 from the MNC group, and 6 from the placebo group. No improvement was seen in the MELD score at month 6 using either CD133+ cells or MNC infusions compared with placebo. However, at month 3 after infusion, a trend was seen toward a higher mean absolute change in the MELD score in patients who had received CD133+ cells compared with placebo (-2.00±1.87 vs. -0.13±1.46; p=.08). No significant adverse events occurred in the present study. A transient improvement in the MELD score was observed in subjects treated with CD133+ cells but not in the MNC or placebo group. Although the study was not powered to make definitive conclusions, the data justify further study of CD133+ therapy in cirrhotic patients.

SIGNIFICANCE

Cell therapy is a new approach in liver disease. Several clinical experiments have been reported on the safety of bone marrow-derived stem cells to treat liver disorders. However, the effectiveness of these approaches in the long-term follow-ups of patients initiated controversial discussions among the scientific community. A double-blind randomized controlled trial was designed to address this concern scientifically. A transient improvement in the patients' signs occurred; however, for a sustainable result, more work is needed. The results of multiple administrations of cells reported in the present study can be compared with the results from other single-injection studies.

miR-92a Corrects CD34+ Cell Dysfunction in Diabetes by Modulating Core Circadian Genes Involved in Progenitor Differentiation

Autologous CD34(+) cells are widely used for vascular repair; however, in individuals with diabetes and microvascular disease these cells are dysfunctional. In this study, we examine expression of the clock genes Clock, Bmal, Per1, Per2, Cry1, and Cry2 in CD34(+) cells of diabetic and nondiabetic origin and determine the small encoding RNA (miRNA) profile of these cells. The degree of diabetic retinopathy (DR) was assessed. As CD34(+) cells acquired mature endothelial markers, they exhibit robust oscillations of clock genes. siRNA treatment of CD34(+) cells revealed Per2 as the only clock gene necessary to maintain the undifferentiated state of CD34(+) cells. Twenty-five miRNAs targeting clock genes were identified. Three of the miRNAs (miR-18b, miR-16, and miR-34c) were found only in diabetic progenitors. The expression of the Per2-regulatory miRNA, miR-92a, was markedly reduced in CD34(+) cells from individuals with DR compared with control subjects and patients with diabetes with no DR. Restoration of miR-92a levels in CD34(+) cells from patients with diabetes with DR reduced the inflammatory phenotype of these cells and the diabetes-induced propensity toward myeloid differentiation. Our studies suggest that restoring levels of miR-92a could enhance the usefulness of CD34(+) cells in autologous cell therapy.

Co-expression of Cytoskeletal Protein Adducin 3 and CD133 in Neurospheres and a Temozolomide-resistant Subclone of Glioblastoma

BACKGROUND

Glioma stem cells are associated for temozolomide-resistance in glioblastoma. Adducin 3 (ADD3) is a cytoskeletal protein associated with chemoresistance but its role in glioblastoma has not been investigated.

MATERIALS AND METHODS

Using an in vitro model of glioblastoma cells with acquired temozolomide resistance (D54-MG-R), the expressions of ADD3 and cancer stem cell markers were compared to those in temozolomide-sensitive glioblastoma cells (D54-MG-S). Immunofluorescence staining was used to investigate the expression patterns of ADD3 and cancer stem cell markers in temozolomide resistance and neurospheres of glioblastoma.

RESULTS

Chemoresistant cells were found to have up-regulation of ADD3 and CD133 expression. A sub-population of D54-MG-R cells and glioma neurospheres exhibited coexpression of ADD3 with CD133.

CONCLUSION

To our knowledge, this is the first report of a possible link between cytoskeletal protein expression, cancer stem cell phenotype and temozolomide resistance in human glioblastoma. This report lays the foundation for further investigation for ADD3 as a potential biomarker and therapeutic target in temozolomide-resistant glioma cells.

CD133 Expression in Lymph Node Metastases Is Associated with Tumor Aggressiveness During Lymph Node Metastasis in Colorectal Cancer

BACKGROUND

Recently, two meta-analysis reports have suggested that CD133 expression in the primary tumor is significantly associated with shorter survival in colorectal cancer (CRC), and that CD133 may play an important role in CRC progression. However, the expression of CD133 in lymph node metastases as well as in primary tumors in CRC remains to be elucidated.

MATERIALS AND METHODS

We analyzed CD133 expression in both primary tumors and lymph node metastases in stage III CRC by immunohistochemistry, and its correlation with clinicopathological factors and outcomes.

RESULTS

Through immunohistochemistry we demonstrated that 69.6% of CRC primary tumors and 62.3% of lymph node metastases were CD133-positive. High CD133 expression in lymph node metastases was significantly associated with the number of lymph node metastases. Moreover, patients with CD133-negative staining of either primary tumor or lymph node metastases had a higher overall survival rate than those with CD133-positive staining, although this finding was not statistically significant.

CONCLUSION

CD133-positive cancers may be more aggressive than CD133-negative ones during the process of lymph node metastasis. Further investigation of the role of CD133-positive cells in lymph node metastases in CRC is required.

IL-6 signaling promotes DNA repair and prevents apoptosis in CD133+ stem-like cells of lung cancer after radiation

BACKGROUND

Local tumor control by standard fractionated radiotherapy (RT) remains poor because of tumor resistance to radiation (radioresistance). It has been suggested that cancer stem cells (CSCs) are more radioresistant than non-CSCs. In previous studies, we have shown IL-6 promotes self-renewal of CD133+ CSC-like cells. In this study, we investigated whether IL-6 plays roles not only in promoting self-renewal of CD133+ cells after radiation, but also in conferring radioresistance of CD133+ cells in NSCLC.

MATERIALS AND METHODS

To compare radiation sensitivity of CSCs and non-CSCs, CD133+ CSC-like and CD133- cell populations were isolated from two NSCLC cell lines, A549 and H157, by immunomagnetic separation and their sensitivities to ionizing radiation were investigated using the clonogenic survival assay. To further study the IL-6 effect on the radiosensitivity of CD133+ CSC-like cells, CD133+ cells were isolated from A549IL-6si/sc and H157IL-6si/sc cells whose intracellular IL-6 levels were manipulated via the lentiviral transduction with IL-6siRNA. Post-irradiation DNA damage was analyzed by γ-H2AX staining and Comet assay. Molecular mechanisms by which IL-6 regulates the molecules associated with DNA repair and anti-apoptosis after radiation were analyzed by Western blot and immunofluoresecence (IF) staining analyses.

RESULTS

NSCLC CD133+ CSC-like cells were enriched upon radiation. Survival of NSCLC CD133+ cells after radiation was higher than that of CD133- cells. Survival of IL-6 expressing NSC LC CD133+ cells (sc) was higher than that of IL-6 knocked-down cells (IL-6si) after radiation. IL-6 played a role in protecting NSCLC CD133+ cells from radiation-induced DNA damage and apoptosis.

CONCLUSIONS

IL-6 signaling promotes DNA repair while protecting CD133+ CSC-like cells from apoptotic death after radiation for lung cancer. A combined therapy of radiation and agents that inhibit IL-6 signaling (or its downstream signaling) is suggested to reduce CSC-mediated radioresistance in lung cancer.

Immunohistochemical expression of cancer stem cell related markers CD44 and CD133 in endometrial cancer

The goal of this study was to detect the presence of cancer stem cell markers CD44 and CD133 in immunohistochemically stained samples of endometrial cancer and correlate their expression with clinicopathological variables to identify the impact of CD44 or CD133 expression on tumor behavior and endometrial carcinogenesis. Marker expression was analyzed in 62 endometrial cancer samples (57 endometrioid carcinoma and 5 carcinosarcoma) and 15 proliferative endometrium samples. We detected CD133 and CD44 expression in 87.09% and 79.03% respectively of the studied endometrial cancers, and the expression was significantly different from the normal group. CD44 expression decreased with myometrial invasive depth and lymph-vascular space invasion (LVSI), and these inverse relationships were significant (p=0.034, p=0.019, respectively). CD133 was more expressed by early stage tumor (FIGO I-II) compared with those having FIGO III to IV stage disease (p=0.021). The most notable conclusion of the present study is that CD44 and CD133 might participate in early-stage endometrial cancer carcinogenesis, and their overexpression may facilitate the early diagnosis of endometrial cancers. Analysis of our results supports the hypothesis that CD44 expression tends to decrease as the disease becomes invasive and progressive. So, we concluded that CD44 down-regulation might warn of a more aggressive course and may have a link with poorly prognosis carcinosarcomas. Further examination of the expression and function of CD44 and CD133 with a greater number of carcinosarcomas is warranted.

Control of AC133/CD133 and impact on human hematopoietic progenitor cells through nucleolin

AC133 is a prominent surface marker of CD34+ and CD34- hematopoietic stem/progenitor cell (HSPC) subsets. AC133+ HSPCs contain high progenitor cell activity and are capable of hematopoietic reconstitution. Furthermore, AC133 is used for prospective isolation of tumor-initiating cells in several hematological malignancies. Nucleolin is a multifunctional factor of growing and cancer cells, which is aberrantly active in certain hematological neoplasms, and serves as a candidate molecular target for cancer therapy. Nucleolin is involved in gene transcription and RNA metabolism and is prevalently expressed in HSPCs, as opposed to differentiated hematopoietic tissue. The present study dissects nucleolin-mediated activation of surface AC133 and its cognate gene CD133, via specific interaction of nucleolin with the tissue-dependent CD133 promoter P1, as a mechanism that crucially contributes to AC133 expression in CD34+ HSPCs. In mobilized peripheral blood (MPB)-derived HSPCs, nucleolin elevates colony-forming unit (CFU) frequencies and enriches granulocyte-macrophage CFUs. Furthermore, nucleolin amplifies long-term culture-initiating cells and also promotes long-term, cytokine-dependent maintenance of hematopoietic progenitor cells. Active β-catenin, active Akt and Bcl-2 levels in MPB-derived HSPCs are nucleolin-dependent, and effects of nucleolin on these cells partially rely on β-catenin activity. The study provides new insights into molecular network relevant to stem/progenitor cells in normal and malignant hematopoiesis.

[Expressions of WWOX and CD133 in colorectal cancer and their clinical significance]

OBJECTIVE

To investigate the expressions of WWOX and CD133 in colorectal cancer (CRC) and their relationship with the clinicopathologic characteristics of CRC.

METHODS

The expressions of WWOX and CD133 proteins were examined by immunohistochemistry in 174 specimens of CRC tissues and 80 normal colorectal mucosa tissues.

RESULTS

The positivity rates of WWOX and CD133 proteins were 41.4% and 53.4% in CRC tissues, respectively, significantly different from the rates in normal colorectal mucosa tissues (87.5% and 5.0%, respectively; P<0.05). WWOX and CD133 protein expressions were signi- ficantly correlated with the histological grades of the tumors, depth of invasion, lymph node metastasis, and Duke's stages (P<0.05). Spearman analysis showed a negative relationship between the WWOX expression and CD133 expression (P<0.05). Kaplan-Meier survival analysis showed that the overall survival time of CRC patients with a positive expression of WWOX was longer than that of patients with a negative expression of WWOX; the overall survival time of patients with a positive expression of CD133 was shorter than that of the negative patients (P<0.05). COX regression analysis identified positive expressions of WWOX and CD133 protein and Duke's stage as the independent prognostic factors of CRC.

CONCLUSION

Abnormal expressions of WWOX and CD133 might be involved in the initiation, development, invasion, and metastasis of CRC. A combined detection of WWOX and CD133 can help in predicting the progression and prognosis of CRC.

NUMB phosphorylation destabilizes p53 and promotes self-renewal of tumor-initiating cells by a NANOG-dependent mechanism in liver cancer

Stem cell populations are maintained through self-renewing divisions in which one daughter cell commits to a particular fate whereas the other retains the multipotent characteristics of its parent. The NUMB, a tumor suppressor, in conjunction with another tumor-suppressor protein, p53, preserves this property and acts as a barrier against deregulated expansion of tumor-associated stem cells. In this context, NUMB-p53 interaction plays a crucial role to maintain the proper homeostasis of both stem cells, as well as differentiated cells. Because the molecular mechanism governing the assembly and stability of the NUMB-p53 interaction/complex are poorly understood, we tried to identify the molecule(s) that govern this process. Using cancer cell lines, tumor-initiating cells (TICs) of liver, the mouse model, and clinical samples, we identified that phosphorylations of NUMB destabilize p53 and promote self-renewal of TICs in a pluripotency-associated transcription factor NANOG-dependent manner. NANOG phosphorylates NUMB by atypical protein kinase C zeta (aPKCζ), through the direct induction of Aurora A kinase (AURKA) and the repression of an aPKCζ inhibitor, lethal (2) giant larvae. By radioactivity-based kinase activity assays, we showed that NANOG enhances kinase activities of both AURKA and aPKCζ, an important upstream process for NUMB phosphorylation. Phosphorylation of NUMB by aPKCζ destabilizes the NUMB-p53 interaction and p53 proteolysis and deregulates self-renewal in TICs.

CONCLUSION

Post-translational modification of NUMB by the NANOG-AURKA-aPKCζ pathway is an important event in TIC self-renewal and tumorigenesis. Hence, the NANOG-NUMB-p53 signaling axis is an important regulatory pathway for TIC events in TIC self-renewal and liver tumorigenesis, suggesting a therapeutic strategy by targeting NUMB phosphorylation. Further in-depth in vivo and clinical studies are warranted to verify this suggestion.

Cancer stem cells in head and neck cancer: A Mini Review

Head and neck cancer (HNC) is a multifaceted and genomically complex disease and rapidly emerging preclinical and clinical studies have provided a broader landscape of signaling. It is being realized that intra-tumor heterogeneity, genetic and epigenetic mutations considerably challenge wide ranging therapeutics and patients frequently develop locoregional recurrences, second primary tumours and distant metastases. Using high-throughput technologies, it has been revealed that existence of different subpopulations of cells within tumor mass with different phenotypic and functional properties with distinct tumour-initiating potential is responsible to HNC resistance. In light of accumulating evidence reported in recent years, it is now known that different intracellular proteins and cell surface markers have been used to study CSCs. This review provides an overview of CSC biomarkers in HNC treatment and their potential as therapeutic targets in improving the diagnosis, prognosis and treatment of HNC patients for new therapeutic strategies with information about estimation of prognosis and treatment decision. Further studies regarding biomarkers are necessary to determine the specific role of CSCs in HNC which could be useful in development of new therapeutic strategies to eliminate CSCs and maximize clinical outcome. Furthermore, CD44 still need more research in HNC once the studies show contradictions. Studies using lineage tracing and deep sequencing will provide a comprehensive understanding of CSC model and extent to which it is accountable for resistance against therapeutics and carcinogenesis.

Niche Mimicking for Selection and Enrichment of Liver Cancer Stem Cells by Hyaluronic Acid-Based Multilayer Films

Cancer stem cells (CSCs) represent a subpopulation of tumor cells that exhibit capacities for self-renewal, tumor initiation, disease relapse or metastasis, and resistance to chemotherapy and radiotherapy. However, the major obstacle associated with the use of CSCs is the difficulty in their isolation and enrichment. According to recent studies, CSCs share similar properties with normal stem cells, and it has been observed that hyaluronan (HA) plays a key factor in CSCs niches and that HA-mediated CD44 interaction promotes tumor progression. Therefore, HA-based multilayer films were used to fabricate sequential surface properties variation and to mimic CSC niches. A quartz crystal microbalance was used to investigate the layer-by-layer adsorption of PAH/HA multilayer films. Colony formation was observed on a series of poly(allylamine hydrochloride) PAH/HA multilayer films, and cytotoxicity and cell viability were evaluated by MTT, LDH and live/dead assay. It was observed that the cells isolated from (PAH/HA)3 displayed the best colony formation ability and that the expression of CD133/CD44 double positive cells was up-regulated to approximately 70% after 7 days of culture. Furthermore, the cells isolated from (PAH/HA)3 displayed higher chemo-resistance than the control group. The stem-cell-related genes expression of selected cells from (PAH/HA)3 after 7 days of culture was significantly different from that of the control group. In conclusion, this study provides a label-free selection and enrichment system that could serve as a new strategy for the future development of CSC selection and drug evaluation in cancer therapy.

Temozolomide Resistance in Glioblastoma Cell Lines: Implication of MGMT, MMR, P-Glycoprotein and CD133 Expression

Background

The use of temozolomide (TMZ) has improved the prognosis for glioblastoma multiforme patients. However, TMZ resistance may be one of the main reasons why treatment fails. Although this resistance has frequently been linked to the expression of O6-methylguanine-DNA methyltransferase (MGMT) it seems that this enzyme is not the only molecular mechanism that may account for the appearance of drug resistance in glioblastoma multiforme patients as the mismatch repair (MMR) complex, P-glycoprotein, and/or the presence of cancer stem cells may also be implicated.

Methods

Four nervous system tumor cell lines were used to analyze the modulation of MGMT expression and MGMT promoter methylation by TMZ treatment. Furthermore, 5-aza-2’-deoxycytidine was used to demethylate the MGMT promoter and O(6)-benzylguanine to block GMT activity. In addition, MMR complex and P-glycoprotein expression were studied before and after TMZ exposure and correlated with MGMT expression. Finally, the effect of TMZ exposure on CD133 expression was analyzed.

Results

Our results showed two clearly differentiated groups of tumor cells characterized by low (A172 and LN229) and high (SF268 and SK-N-SH) basal MGMT expression. Interestingly, cell lines with no MGMT expression and low TMZ IC₅₀ showed a high MMR complex expression, whereas cell lines with high MGMT expression and high TMZ IC₅₀ did not express the MMR complex. In addition, modulation of MGMT expression in A172 and LN229 cell lines was accompanied by a significant increase in the TMZ IC₅₀, whereas no differences were observed in SF268 and SK-N-SH cell lines. In contrast, P-glycoprotein and CD133 was found to be unrelated to TMZ resistance in these cell lines.

Conclusions

These results may be relevant in understanding the phenomenon of TMZ resistance, especially in glioblastoma multiforme patients laking MGMT expression, and may also aid in the design of new therapeutic strategies to improve the efficacy of TMZ in glioblastoma multiforme patients.

Expression of cancer stem cell markers and their correlation with pathogenesis in vascular tumors

Vascular tumor, which belongs to a kind of complicated lesion in soft tissue tumor, is derived from mesenchymal tissue. Although many studies have been focused on the pathogenesis of vascular tumors in human, the specific mechanism of the vascular tumors was currently unclear. Previous studies have reported an association of cancer stem cells with the development of tumor in many solid tumors. Thus the purpose of this study was to explore whether different expression level of cancer stem cell markers including CD29, CD44, CD133, nestin and ALDH1 in vascular tumor may help to elucidate the possible pathogenesis of vascular tumor. In present study, tissues of 9 cases of hemangioma, 22 cases of hemangiosarcoma, 3 cases of Kaposi's sarcoma, and 5 cases of hemangioendothelioma were immunostained for CD29, CD44, CD133, nestin and ALDH1. Of the 39 vascular tumor cases included in the current study, CD29, CD133 and nestin were positive in most vascular tumor cases. Although CD44 and ALDH1 were observed in vascular tumor cases, the percentage of cells staining for the two markers was less than 2% in all cases of vascular tumor. Capillary hemangiomas exhibited significantly higher expression rate of CD29 and nestin compared with malignant vascular tumors and hemangioendotheliomas (P<0.05, Fisher's exact test), while CD44, CD133 and ALDH1 exhibited no statistically significant difference between these two groups. Pearson correlation analysis exhibited that CD29 expression and nestin expression in vascular tumor were no statistically significant relationship (C=0.288, P=0.063>0.05). Our findings confirmed that the five cancer stem cells markers, including CD29, CD44, CD133, nestin and ALDH1, exhibited different expression levels in vascular tumors and demonstrated that immunohistochemical analysis for cancer stem cells markers may provide useful information for studying the pathogenesis of vascular tumors.

[Reversal of stemness in multidrug-resistant hepatocellular carcinoma cells by SIS3]

OBJECTIVE

To investigate whether SIS3, a specific inhibitor of Smad3 phosphorylation, can reverse the stemness of multidrug-resistant(MDR) hepatocellular carcinoma cells.

METHODS

MDR HCC Huh7.5.1/ADM cell lines were developed by exposing parental cells to stepwise increasing concentrations of ADM. CCK-8 assay was used to determine the cellular sensitivity of various anticancer drugs. Flow cytometry (FCM) was used to analyze the expression level of cancer stem cell marker CD133. Clone formation assay and mouse subcutaneous xenograft tumors were used to investigate the tumorigenicity in vitro and in vivo. Western blotting (WB) was used to analyze the changes of expressions of CD133, Smad3, Bcl-2, Bax and p-Smad3 in different conditions.

RESULTS

ADM treatment of HCC cells in vitro resulted in a development of subline, Huh7.5.1/ADM cells, with CSC phenotypes: stable MDR phenotype (besides ADMc Huh7.5.1/ADM cells were also more resistant to some other anticancer drugs including VCR, MMC and CTX ) (IC50: 0.215 ± 0.018 vs. 0.123 ± 0.004, 0.145 ± 0.009 vs. 0.014 ± 0.002, 1.021 ± 0.119 vs. 0.071 ± 0.006, 27.007 ± 1.606 vs. 1.919 ± 0.032) (unit: µg/ml) (P<0.05). Huh7.5.1/ADM cells enriched the cancer stem-like cell fraction (CD133-positive subpopulation) (76.06 ± 2.948% vs. 25.38 ± 4.349%) (P<0.05), had stronger tumorigenicity in vivo and colony formation ability, and activated the Smad3 activity. Inhibition of Smad3 activity by SIS3 decreased stemness of the Huh7.5.1/ADM cells: CD133-positive subpopulation (48.49 ± 2.304% vs. 76.06 ± 2.948%) (P<0.05); ADM IC50: (0.112 ± 0.019 vs. 0.215 ± 0.018), VCR IC50 (0.065 ± 0.013 vs. 0.145±0.009), MMC IC₅₀ (0.749 ± 0.121 vs. 1.021 ± 0.119), CTX IC50 (10.576 ± 1.248 vs. 27.007 ± 1.606) (unit: µg/ml) (P<0.05), and decreased tumorigenicity and colony formation ability.

CONCLUSION

SIS3 as a specific inhibitor of Smad3 signal is involved in the stemness of multidrug resistant hepatocellular carcinoma cells.

Prognostic value of cancer stem cell marker CD133 expression in pancreatic ductal adenocarcinoma (PDAC): a systematic review and meta-analysis

CD133 is one of the most commonly used markers of pancreatic cancer stem cells (CSCs), which are characterized by their ability for self-renewal and tumorigenicity. Although the expression of CD133 has been reported to correlate with poor prognosis of PDAC in most literatures, some controversies still exist. In this study, we aimed to investigate the correlation between CD133 expression and prognosis and clinicopathological features in PDAC. A search in the Medline, EMBASE and Chinese CNKI (China National Knowledge Infrastructure) database (up to 1 March 2015) was performed using the following keywords pancreatic cancer, CD133, AC133, prominin-1 etc. Data from eligible studies were extracted and included into meta-analysis using a random effects model. Outcomes included overall survival and various clinicopathological features. We performed a final analysis of 723 patients from 11 evaluable studies for prognostic value and 687 patients from 12 evaluable studies for clinicopathological features. Our study shows that the pooled hazard ratio (HR) of overexpression CD133 for overall survival in PDAC was 0.58 (95% confidence interval (CI): 0.49-0.67) by univariate analysis and 0.73 (95% CI: 0.52-1.03) by multivariate analysis. With respect to clinicopathological features, CD133 overexpression by immunohistochemistry (IHC) method was closely correlated with clinical TNM stage (TNM stage III+IV, OR=0.32, 95% CI: 0.19-0.54), tumor differentiation (poor differentiation, OR=0.56, 95% CI: 0.37-0.83), and lymph node metastasis (N1, 3.15, 95% CI: 1.56-6.36) in patients with PDAC. Our meta-analysis results suggest that CD133 is an efficient prognostic factor in PDAC. Overexpression of CD133 was significantly associated with clinical TNM stage, tumor differentiation and lymph node metastasis.

[The cultivation and identification of lacrimal gland adenoid cystic cancer stem cells]

OBJECTIVE

To isolate and cultivate the Lacrimal gland Adenoid Cystic Carcinoma cells line, study Cancer Stem Cells properties.

METHOD

Experimental study. Lacrimal gland adenoid cystic carcinoma cancer stem cells were cultivated in serum-free suspension culture and the morphological changes were observed. Cells were divided into two groups, the LACC-CSC experimental group and the LACC control group. The flow cytometry instrument was used to detect the expression of classical stem cell markers CD133 and ABCG2. Transwell chamber was used to detect the cancer stem cell aggressivity and differentiated into the vascular endothelial cells. The tumorigenic force in vitro xenotransplantation were applied.

RESULT

LACC cells can grow suspensively after vaccinated in serum free medium and form tumor microspheres after 10-12 days. Flow cytometry experiments showed that the expression ratio of stem cell markers CD133 in LACC-CSC was (35.67 ± 6.86)%, significantly different to LACC with (0.46 ± 0.48)%, (t = 8.867, P < 0.05). Similarly, the expression ratio of stem cell marker ABCG2 in LACC-CSC was (39.99 ± 4.54)%, significantly different to LACC with (6.75 ± 1.34)%, (t = -9.932, P < 0.05). In vitro experiment of Matrigel invasion, LACC-CSC went through the matrigel basement membrane averagely (32.60 ± 8.79)/HP contrary to LACC with average (10.20 ± 2.77)/HP after 24 hours, showing statistically significance (t = 5.433, P < 0.05) between the two groups. After training for 48 hours, the difference between two groups was still obvious (t = 5.779, P < 0.05) with LACC-CSC average (62.60 ± 4.83)/HP to LACC (44.00 ± 5.34)/HP. When induced by serum medium containing VEGF and bFGF, LACC-CSC grew adherent gradually and cell morphological changes occurred after continuous induction to long spindle cells. When cultured into three-dimensional matrix structure they formed vessel samples and expressed vascular endothelial marker CD31 and CD34. Transplanted tumor in vitro experiment, mice of LACC-CSC group grew tumors in 9 days with 100% tumorigenic rate, whereas LACC group 12 days with 100% tumorigenic rate.

CONCLUSIONS

LACC-CSC can be obtained through serum-free culture method. LACC-CSC grew suspensively and expressed classical stem cell markers. LACC-CSC were identified as cancer stem cells with stronger migration and invasion. LACC-CSC have tumorigenic force and multi-directional differentiation potential with general characteristics of the stem cell.

Constitutive secretion of Interleukin-4 dictates CD133+ side population cells to resist drug treatment and cell death

PURPOSE

In the present study, we made an attempt to elucidate the role of oversecretion of interleukin-4 (IL-4) in cancer stem cells (CSCs) of head and neck squamous cell carcinoma (HNSCC).

METHODS

HNSCC samples were analyzed for the presence of CSCs by flow cytometry. In addition, we have performed drug and apoptosis resistance assays to determine the role of IL-4 in CSCs.

RESULTS

HNSCC samples contained 3.3% of CD133+ cancer stem like side population (SP) cells in HNSCC which displayed infinite cell proliferation and they had high self-renewal capacity. These CD133+ cells displayed enhanced expression of IL-4, which promoted multidrug and apoptosis resistance. After neutralizing IL-4, the CD133+ SP cells became more sensitive to drug treatment and apoptosis.

CONCLUSIONS

Our data suggest that the autocrine secretion of IL-4 is a potential target for the development of novel anticancer drugs to prevent the CSCs-mediated therapy failure and tumorigenesis.

Establishment of pancreatic cancer stem cells by flow cytometry and their biological characteristics

To investigate the method of separating human pancreatic cancer stem cells by Hoechst 33342 labeled flow cytometry and to analyze the biological properties of pancreatic cancer stem cells. The human pancreatic cancer cell line PC-3 was divided into SP and non-SP cells by flow cytometry. The number of two cell clone spheres and nude mice tumor formation rates were compared by cultivating in serum-free medium; The expression of CD133, Nestin mRNA and protein was analyzed by real-time fluorescence quantitative PCR and Western blot; The expression of two cell drug resistance genes (MDR1, ABCG2, ABCA2 and MRP1) was analyzed by real time fluorescent quantitative PCR. The number of the cloned spheres in SP cells in serum-free medium was significantly higher than that of non-SP cells (P<0.05). The incidence of SP cells in the tumor of immunodeficiency nude mice was significantly higher than that of non-SP cells, and the difference was statistically significant (P<0.05). Real-time fluorescence quantitative PCR analysis showed that the expression of CD133 and Nestin mRNA in SP cells was significantly higher than those of non-SP cells, and the expression of CD133 and Nestin protein in SP cells was also significantly higher than those of non-SP cells (P<0.05). In conclusion, SP side population pancreatic cancer cells by Hoechst 33342 separation have the stem cell characteristics, higher tumor formation rate and higher drug resistance, which may be related to chemotherapy resistance.